[DOC] Update `String#encode` special case

This behavior has been slightly extended with the addition of
`String#scrub`.

1 files changed, 5 insertions, 4 deletions

diff --git a/doc/string/encode.rdoc b/doc/string/encode.rdoc
index a7d400724d..65872fdfd4 100644
--- a/doc/string/encode.rdoc
+++ b/doc/string/encode.rdoc
@@ -39,8 +39,9 @@ interprets +self+ using +src_encoding+, encodes the new string using +dst_encodi
 Optional keyword arguments +enc_opts+ specify encoding options;
 see {Encoding Options}[rdoc-ref:encodings.rdoc@Encoding+Options].
 
-Please note that conversion from an encoding +enc+ to the same encoding
-+enc+ (independent of whether +enc+ is given explicitly or implicitly)
-is a no-op, i.e. the string is simply copied without any changes, and
-no exceptions are raised, even if there are invalid bytes.
+Please note that, unless <code>invalid: :replace</code> option is
+given, conversion from an encoding +enc+ to the same encoding +enc+
+(independent of whether +enc+ is given explicitly or implicitly) is a
+no-op, i.e. the string is simply copied without any changes, and no
+exceptions are raised, even if there are invalid bytes.